Bookmarks can be quite fickly in Spotfire.  When the user creates a bookmark, versus a bookmark special, absolutely everything about the analysis is captured, and if anything at all changes, it can break the bookmark.  This is especially frustrating with tables.  I have created bookmarks where a table is present on the page, and then I rearrange columns or add columns, and the bookmark is no longer as I intend.  As a result, I have taken to the habit of only using bookmark specials to capture precisely what I want.  Bookmark specials are accessed by right clicking on the plus sign in the bookmarks panel.